A method and device for defect detection of copper rod blanks

Abstract

The present invention relates to the field of copper rod blank detection technology, and more particularly to a defect detection method and apparatus for copper rod blanks. The method comprises the following steps: S10: preparing a quality grade table for the copper rod blank; placing the copper rod blank on a conveyor roller and starting the conveyor roller; S20: adjusting the conveyor roller speed to drive the copper rod blank to the front of a detection zone along the conveying direction, activating an electromagnetic rotation drive device and an electromagnetic induction detection module; S30: using a second control unit and a second current regulator to control the activation of a second electromagnetic coil, causing an electromagnetic sensor to detect defect signals, calculate an induced voltage, and collect defect information of the copper rod blank; S40: calculating an intensity factor X1, a destructiveness factor X2, and an influence factor X3 based on the defect information; calculating a defect score Q = W1·X1+W3·X2+W3·X3 for the copper rod blank; and grading the copper rod blank according to the quality grade table. The method effectively reduces the missed detection rate of copper rod blank defects and accurately identifies internal defects.

Description

Technical Field

[0001] The present invention relates to the technical field of copper rod blank detection, and in particular to a defect detection method and equipment for copper rod blanks. Background Art

[0002] At present, copper rod billets, as metal materials with excellent conductive properties, are widely used as raw materials in cables, power facilities and other fields; however, during the production process, copper rod billets are prone to defects such as internal cracks, pores, inclusions and surface scratches due to raw material defects, poor processing technology or external environmental factors. These defects not only affect the yield of subsequent processing, but may also cause the performance of the final product to deteriorate or even fail.

[0003] Existing copper rod blank defect detection methods mainly rely on manual visual inspection or simple mechanical inspection. Especially for short copper rod blanks, manual inspection requires checking each one one by one, which is labor-intensive and difficult to meet the needs of mass production. It is also impossible to evaluate the comprehensive defect impact of each copper rod blank. Traditional mechanical inspection cannot accurately identify tiny internal defects. Some mechanical inspections not only damage the copper rod blanks, but are also prone to omissions. They lack intelligent analysis and automatic processing of defect information and cannot support automated operations on the production line.

[0004] Therefore, there is an urgent need for a method and equipment that can effectively detect defects in short copper rod blanks. Summary of the Invention

[0005] The present invention provides a defect detection method and device for copper rod blanks, which can effectively detect defects in copper rod blanks, effectively reduce the defect missed detection rate, and accurately identify tiny defects inside the copper rod blanks.

[0006] The present invention provides a defect detection method for a copper rod blank, comprising the following steps:

[0007] S10: Formulate a quality grade table for copper rod blanks; prepare the copper rod blanks to be tested and start conveying the copper rod blanks;

[0008] S20: adjusting the conveying speed, driving the copper rod blank to move along the conveying direction to the inspection area, rotating the copper rod blank at a certain speed and starting to inspect defects of the copper rod blank;

[0009] S30: turning on the induction magnetic field, using the induction coil to detect the defect signal of the copper rod blank in real time, calculating the induced voltage and collecting the defect information of the copper rod blank;

[0010] S40: Calculate the density factor X1, the destructiveness factor X2, and the influence factor X3 based on the defect information; calculate the defect score Q = W1·X1+W3·X2+W3·X3 of the copper rod blank, where W1, W2, and W3 are weight coefficients; and grade the copper rod blank according to the quality grade table.

[0011] Furthermore, in step S30, the specific calculation of the induced voltage is:

[0012] The detection time t starts from 0 when the copper rod billet enters the induction coil;

[0013] Induced voltage V(t) = -N [dΦ(t) / dt];

[0014] Where N is the number of turns of the induction coil; the magnetic flux Φ(t) at time t = B(t)·A, B(t) is the magnetic induction intensity at time t, and A is the cross-sectional area of ​​the induction coil.

[0015] Furthermore, in step S30, the defect information specifically includes:

[0016] Assume that n defects are detected in total, and the defects are numbered 1, 2, ... n in the order of detection;

[0017] Calculate the defect depth dn = k1·ΔVn and the defect length ln = v·ΔTn of the defect at position n;

[0018] Where k1 is the depth coefficient; ΔVn is the range of the induced voltage at the nth defect; v is the transmission speed of the copper rod blank; and ΔTn is the duration of the nth defect.

[0019] Furthermore, in step S30, the defect information also includes the defect quantity Nd:

[0020] statistics

[0021] Among them, Detect is the judgment function; ΔV i is the extreme difference of the induced voltage at the i-th defect; Δt i is the time interval between the i-th defect and the i-1-th defect.

[0022] Furthermore, in step S30, the judgment function Detect is specifically:

[0023] Construction

[0024] Among them, V t is the set voltage change threshold, which is a constant; t min is the minimum interval time between two sensing signals.

[0025] Furthermore, in step S40, the density factor X1, the destructiveness factor X2, and the influence factor X3 are specifically calculated as follows:

[0026] Density factor X1 = Nd / L; Destruction factor Influence factor X3 = (l1 + ... ln) / L;

[0027] The specific calculation method of the defect score Q is updated as follows:

[0028]

[0029] Wherein, L is the total length of the copper rod blank; is the diameter of the copper rod blank.

[0030] Furthermore, step S40 also includes storing the defect information, defect score and defect grade of the copper rod blank and generating a test report; and classifying and storing copper rod blanks of different grades.

[0031] The present invention also provides a defect detection device for copper rod blanks, which is used in the above-mentioned defect detection method for copper rod blanks, comprising:

[0032] Transmission rack, mounted on the ground;

[0033] The conveying roller is arranged on the conveying frame and is used to convey the copper rod blank to be tested; the conveying roller is provided with a plurality of semi-circular supporting claws at intervals; the supporting claws are opened upward, and the lowest inner wall thereof is flush with the upper end surface of the conveying roller when viewed in the horizontal direction, and is used to support the copper rod blank; a testing area is provided in the middle section of the conveying roller;

[0034] An electromagnetic rotation drive device is provided at each end of the detection area along the conveying direction of the conveying roller and is connected to the conveying frame; the electromagnetic rotation drive device includes a first electromagnetic coil, a first current regulator and a first control unit;

[0035] The first electromagnetic coil is annular in shape, with its opening facing the transport direction of the conveying roller, and the lowest end of the first electromagnetic coil is lower than the conveying roller, and the inner wall diameter of the first electromagnetic coil is larger than the diameter of the copper rod blank;

[0036] The first current regulator is connected to the first electromagnetic coil, and the first control unit is installed on one side of the first electromagnetic coil and is used to control the rotation of the copper rod blank;

[0037] The electromagnetic induction detection module is installed in the detection area, connected to the transmission frame, and located above the transmission roller. It is used to detect internal and surface defects of the copper rod blank.

[0038] Furthermore, the electromagnetic induction detection module includes a second electromagnetic coil, an electromagnetic sensor, a second current regulator and a second control unit; the second electromagnetic coil is coaxial with the support claw and fixedly connected to the transmission frame; the electromagnetic sensor is arranged on one side of the second electromagnetic coil and connected to the transmission frame; the second current regulator is connected to the second electromagnetic coil, and the second control unit is installed on one side of the second electromagnetic coil for controlling the second electromagnetic coil.

[0039] Furthermore, the electromagnetic sensor includes multiple groups of independent induction coils, which are spirally arranged at different positions around the axis of the copper rod blank along the transmission direction of the transmission roller, and the spiral direction is opposite to the rotation direction of the copper rod blank.

[0040] The method and device of the present invention can achieve the following technical effects:

[0041] By using two electromagnetic rotary drive devices to drive the rotation of the copper rod blank to be tested, and cooperating with the electromagnetic induction detection module to detect the copper rod blank, it is beneficial to achieve non-destructive and efficient detection of the copper rod blank during the transmission process; the spirally distributed electromagnetic sensors can detect defects in the copper rod blank more comprehensively, reducing the possibility of missed defects; by calculating the depth, length and number of defects in the copper rod blank and grading them according to the quality grade, it is beneficial to improve the reliability of the test results and enhance the accuracy of detecting tiny defects inside the copper rod blank. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 1 is a flow chart of the steps of a defect detection method for a copper rod blank according to the present invention;

[0044] Figure 2 This is a schematic structural diagram of a defect detection device for copper rod blanks according to the present invention;

[0045] Figure numerals: 1. Transmission frame; 2. Transmission roller; 21. Support claw; 22. Detection area; 3. Electromagnetic rotation drive device; 31. First electromagnetic coil; 4. Electromagnetic induction detection module; 41. Second electromagnetic coil; 42. Electromagnetic sensor; 421. Induction coil. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0047] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by “center”, “up”, “down”, “left”, “right”, “vertical”, “horizontal”, “inside” and “outside”, etc., are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0048] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; they may refer to mechanical or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0049] A defect detection method for copper rod blanks, such as Figure 1 As shown, the following steps are included:

[0050] S10: Develop a quality grade table for copper rod blanks; prepare the copper rod blanks to be tested and place them on the support claws 21 at one end of the starting point of the conveyor roller 2, and start conveying the copper rod blanks using the conveyor roller 2;

[0051] S20: The conveying speed is adjusted by adjusting the speed of the conveying roller 2. When the copper rod blank is moved along the conveying direction to the area to be tested, i.e., in front of the detection area 22, the electromagnetic rotary drive device 3 is used to rotate the copper rod blank at a certain speed, and the electromagnetic induction detection module 4 is used to start detecting defects in the copper rod blank.

[0052] S30: Using the second control unit and the second current regulator to control the start of the second electromagnetic coil 41 to control the start of the induced magnetic field, using the electromagnetic sensor 42 to detect the defect signal of the copper rod blank, calculate the induced voltage and collect the defect information of the copper rod blank;

[0053] S40: Calculate the density factor X1, the destructiveness factor X2, and the influence factor X3 based on the defect information; calculate the defect score Q of the copper rod blank = W1·X1+W3·X2+W3·X3, where W1, W2, and W3 are manually set weight coefficients and are constants; and grade the copper rod blank according to the quality grade table.

[0054] The specific working principle of the present invention is as follows:

[0055] With reference to industry standards or specifications, combined with the different uses of copper rod blanks, targeted statistics and analysis of large-scale inspection data are conducted to formulate a quality registration form for copper rod blanks.

[0056] After the copper rod blank to be tested is prepared, it is placed on the support claws 21 of the conveying roller 2 and the copper rod blank begins to be conveyed; the semi-annular support claws 21 are opened upward, and the inner diameter of the ring is slightly larger than the outer diameter of the copper rod blank, so that the copper rod blank can move forward along the straight line formed by the spaced support claws 21 and will not roll arbitrarily on the conveying roller 2.

[0057] The speed of conveying the copper rod blank is adjusted to drive the copper rod blank to move along the transmission direction to the detection area. Electromagnetic rotation drive devices 3 are set at both ends of the detection area 22. A uniform rotating magnetic field is generated on the surface of the copper rod blank by the first electromagnetic coil 31 in the electromagnetic rotation drive device 3, thereby driving the copper rod blank to rotate at a certain speed after being subjected to force; and after the entire copper rod blank enters the detection area 22, it can rotate along with the transmission direction of the conveyor roller 2. The defects of the copper rod blank are detected by using the electromagnetic induction detection module 4, so that the entire surface of the copper rod blank can be detected in all directions without blind spots.

[0058] The second electromagnetic coil 41 in the electromagnetic induction detection module 4 is controlled to activate an induced magnetic field. The changing electromagnetic field induces the flow of internal current in the conductor, i.e., the copper rod blank in the present invention. Induction signals from the copper rod blank are collected in real time in conjunction with the multiple sets of spirally distributed induction coils 421. Specifically, when a metal object, such as a copper rod blank, is exposed to an alternating magnetic field, induced currents are generated within it. The magnitude and shape of these induced currents are directly related to the structural characteristics of the metal object (e.g., defects such as cracks and pores). By detecting changes in these induced currents, defects within or on the surface of the metal object can be inferred. Therefore, in the present invention, defect signals are obtained through changes in the induced signals, and defect information within and on the surface of the copper rod blank is obtained based on the defect signals. The change in the induced voltage is then calculated, and information such as the defect depth, location, and length is extracted using a formula. The copper rod blank is then quality-graded based on the defect score.

[0059] After the inspection is completed, the equipment automatically sorts the copper rod blanks according to the defect level and stores them in categories. At the same time, it stores the inspection report to provide data support for production process optimization.

[0060] In some embodiments of the present invention, in step S30, the specific calculation of the induced voltage is:

[0061] The detection time t is measured starting from 0 when the copper rod blank enters the induction coil (421);

[0062] Induced voltage V(t) = -N [dΦ(t) / dt];

[0063] Wherein, N is the number of turns of the electromagnetic sensor 421; the magnetic flux Φ(t) at time t = B(t)·A, B(t) is the magnetic induction intensity at time t, and A is the cross-sectional area of ​​the electromagnetic sensor 421;

[0064] This formula uses the derivative with respect to time t to describe the change of magnetic flux over time, converting the change of magnetic flux Φ(t) into an induced voltage signal, reflecting the relationship between the disturbance of the magnetic field caused by defects in the copper rod blank and the induced signal, reducing complex signal processing steps. It is suitable for real-time monitoring of dynamic defect signals of copper rod blanks during transmission and rotation, improving the accuracy and efficiency of detection. The change in magnetic induction intensity B(t) caused by the defect is directly reflected in the change in induced voltage V(t), which can accurately capture the weak magnetic field disturbance caused by the defect and effectively improve the recognition accuracy of small defects such as small cracks and pores.

[0065] The number of turns N and cross-sectional area A of the electromagnetic sensor 421 can also be adjusted to meet the detection requirements of copper rod blanks of different specifications; and the combination of the electromagnetic sensor 421 and the voltage signal avoids the complex hardware equipment requirements in traditional mechanical or optical detection, while improving the detection speed.

[0066] Preferably, in step S30, the defect information specifically includes:

[0067] Assume that n defects are detected in total, and the defects are numbered 1, 2, ... n in the order of detection;

[0068] Calculate the defect depth dn = k1·ΔVn and the defect length ln = v·ΔTn of the defect at position n;

[0069] Where k1 is the depth coefficient; ΔVn is the range of the induced voltage at the nth defect; v is the transmission speed of the copper rod blank; and ΔTn is the duration of the nth defect.

[0070] The extreme difference in induced voltage can reflect the depth information of the copper rod blank defect, which directly reflects the impact of the defect on the material integrity. The length of each defect is calculated by the duration ΔT of the defect signal at each location, and the spatial range of the defect can be determined by combining the defect depth d.

[0071] In some embodiments of the present invention, the calculation of the defect position can be added: defect position x = v·T; where v is the transmission speed of the copper rod blank on the transmission roller 2; T is the time point when a defect signal is detected, reflecting the instantaneous position of the defect in the detection area 22; simply by using the transmission speed v and time T, the time of signal occurrence can be mapped to the physical position of the copper rod blank; with the defect position, the position of each defect can be accurately located, and targeted preparatory work can be carried out when repairing equipment or processing the area where the defect is located; it can also be combined with the defect number Nd to assist in counting and avoid repeated counting of the defect number Nd.

[0072] In step S30, the defect information also includes the defect number Nd:

[0073] statistics

[0074] Among them, Detect is the judgment function; ΔV i is the extreme difference of the induced voltage at the i-th defect; Δt i is the time interval between the i-th defect and the i-1-th defect;

[0075] This formula traverses all sensing signals, counts the sampling points of all detected defect signals, selects the number of defect signals that meet the conditions, and adds them up to obtain the number of defects Nd; it effectively avoids the problems of misjudgment and missed detection that occur in traditional statistical methods.

[0076] Preferably, in step S30, the judgment function Detect is specifically:

[0077] Construction

[0078] Among them, V t It is an artificially set voltage change threshold, which is a constant; t min It is the minimum interval time between two sensing signals obtained after calculation, preferably calculated based on the transmission speed and detection resolution of the copper rod blank.

[0079] The advantage of designing this formula is that if a sensing signal continuously exceeds the threshold for a period of time, it is considered to be the same defect signal sampling point; when the signal returns to a state below the threshold and exceeds the threshold again, it is considered that a new defect signal sampling point is detected; however, in order to avoid repeated counting, the time judgment is added; when the voltage change ΔV of the sensing signal exceeds the set threshold V t And the time interval Δt between the two sensing signals i More than t min When , it is counted as an independent defect signal; finally, after traversing all the sensing signals, the sensing signal that meets the conditions is recorded as the defect signal.

[0080] In some embodiments of the present invention, in step S40, the density factor X1, the destructiveness factor X2, and the influence factor X3 are specifically calculated as follows:

[0081] Density factor X1 = Nd / L; Destruction factor Influence factor X3 = (l1 + ... ln) / L;

[0082] The specific calculation method of the defect score Q is updated as follows:

[0083]

[0084] Wherein, L is the total length of the copper rod blank; is the diameter of the copper rod blank.

[0085] The calculation of the defect score Q links the number of defects Nd, defect depth d, and defect length l with the total length L of the copper rod blank. The number of defects Nd represents the overall density of defects; the more defects, the worse the quality. The average value of all defect depths d over the entire copper rod blank reflects the degree of damage to the strength of the copper rod blank caused by the defects; the greater the depth, the more severe the defect. The average value of all defect lengths l over the entire copper rod blank describes the extension range of the defects; the greater the length, the larger the affected area of ​​the copper rod blank. The comprehensive distribution of the impact of all defects on the copper rod blank over the entire copper rod blank solves the problem that traditional manual or single indicator evaluation cannot reflect the comprehensive impact of defects and quantifies the overall quality of the copper rod blank.

[0086] Step S40 also includes storing the defect information, defect score and defect grade of the copper rod blank and generating an inspection report to facilitate historical comparison of the quality of different production batches and provide data support for process optimization; copper rod blanks of different grades are classified and stored, so that they are allocated to different processing processes or sales channels according to grade, thereby improving product utilization and reducing the impact of defective products on overall production; such full-process inspection and storage greatly improves inspection efficiency and management capabilities.

[0087] The present invention also provides a defect detection device for copper rod blanks, such as Figure 2 Shown, including:

[0088] The transmission frame 1 is installed on the ground and can be connected with the production and subsequent processing of copper rod blanks to form a smooth and continuous automated production line, reducing the need for personnel; a power source can be set in the gap between the transmission frame 1 to provide power to the transmission roller 2;

[0089] The conveyor roller 2 is provided on the conveyor frame 1 and is used to convey the copper rod blank to be tested. The conveyor roller 2 is provided with a plurality of semi-circular support claws 21 at intervals. The support claws 21 are opened upward, and the lowest inner wall thereof is flush with the upper end surface of the conveyor roller 2 when viewed in the horizontal direction. The support claws 21 are used to support the copper rod blank. In this way, when the copper rod blank moves on the conveyor roller 2, the support claws 21 restrict movement to both sides, thereby helping the copper rod blank to rotate along a straight line within the support claws 21 without affecting the movement of the copper rod blank along the conveying direction of the conveyor roller 2. A detection area 22 is provided in the middle section of the conveyor roller 2.

[0090] The electromagnetic rotation drive device 3 is provided at each end of the detection area 22 along the transport direction of the transport roller 2 and is connected to the transport frame 1. The electromagnetic rotation drive device 3 includes a first electromagnetic coil 31, a first current regulator and a first control unit.

[0091] When the copper rod is in the magnetic field generated by the electromagnetic rotation drive device, as the magnetic field changes over time, eddy currents are induced inside the copper rod. The eddy currents are generated by Faraday's law of electromagnetic induction, and the direction of the eddy currents is related to the direction of change of the magnetic field. The eddy currents form a circular closed current inside the copper rod. These currents are acted upon by the Lorentz force in the magnetic field, generating a torque, thereby driving the copper rod to rotate.

[0092] The first electromagnetic coil 31 is annular in shape, with its opening facing the transport direction of the conveyor roller 2, and the lowest end of the first electromagnetic coil 31 is lower than the conveyor roller 2. The inner wall diameter of the first electromagnetic coil 31 is larger than the diameter of the copper rod blank.

[0093] The first current regulator is connected to the first electromagnetic coil 31, and the first control unit is installed on one side of the first electromagnetic coil 31 to control the rotation of the copper rod blank;

[0094] The electromagnetic induction detection module 4 is installed in the detection area 22, connected to the transmission frame 1, and located above the transmission roller 2, and is used to detect internal and surface defects of the copper rod blank.

[0095] Preferably, the electromagnetic induction detection module 4 includes a second electromagnetic coil 41, an electromagnetic sensor 42, a second current regulator, and a second control unit. The electromagnetic induction module can accurately identify various defects such as internal cracks, pores, and surface scratches in the copper rod blank by inducing changes in the magnetic field, thereby achieving non-destructive testing and protecting the integrity of the copper rod blank. The second electromagnetic coil 41 is coaxial with the support claw 21 and is fixedly connected to the transmission frame 1 to generate a uniform and stable induced magnetic field that covers the entire surface of the copper rod blank, ensuring that the copper rod blank can be fully detected during rotation. The electromagnetic sensor 42 is arranged on one side of the second electromagnetic coil 41 to collect magnetic field changes caused by internal or surface defects in the copper rod blank in real time, convert the induced signal into an electrical signal reflecting the depth, location, and length of the defect, and is connected to the transmission frame 1 to avoid errors caused by equipment movement or vibration, thereby improving the reliability of the detection results. The second current regulator is connected to the second electromagnetic coil 41, and the second control unit is installed on one side of the second electromagnetic coil 41 for controlling the second electromagnetic coil 41. By dynamically adjusting the current, the induction strength of the electromagnetic coil is controlled to adapt to copper rod blanks of different specifications, thereby ensuring the sensitivity and adaptability of the detection.

[0096] Preferably, the electromagnetic sensor 42 includes multiple groups of independent induction coils 421, which are spirally arranged at different positions around the axis of the copper rod blank along the transmission direction of the transmission roller 2, and the spiral direction is opposite to the rotation direction of the copper rod blank, which can form an alternating effect with the dynamic rotational movement of the copper rod blank. The axis of the induction coil 421 is parallel to the axis of the copper rod blank when it is transmitted on the transmission roller 2, which ensures that each induction coil 421 can cover different areas during the rotation of the copper rod blank, forming a comprehensive detection and avoiding repeated detection of the same defect; and the independent multiple groups of induction coils 421 can better adjust the angle and spacing, and can flexibly adapt to copper rod blanks of different diameters and specifications, thereby enhancing the adaptability of the equipment.

[0097] The three coils described above have different functions but are also interrelated. The first electromagnetic coil 31 is responsible for driving the rotation of the copper rod to be tested, the second electromagnetic coil 41 is responsible for generating the detection magnetic field, and the induction coil 421 is responsible for signal acquisition. The three coils work together to realize an efficient, accurate, and non-destructive defect detection system.

[0098] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A defect detection method for copper rod blanks, characterized in that: The steps include: S10: Formulate a quality grade table for copper rod blanks; prepare the copper rod blanks to be tested and start conveying the copper rod blanks; S20: adjusting the conveying speed, driving the copper rod blank to move along the conveying direction to the inspection area, rotating the copper rod blank at a certain speed and starting to inspect defects of the copper rod blank; S30: turning on the induction magnetic field, using the induction coil (421) to detect the defect signal of the copper rod blank in real time, calculating the induced voltage and collecting the defect information of the copper rod blank; The specific calculation of the induced voltage is: The detection time t is measured starting from 0 when the copper rod blank enters the induction coil (421); Induced voltage V(t) = -N [dΦ(t) / dt]; Wherein, N is the number of turns of the induction coil (421); the magnetic flux Φ(t) at time t=B(t)·A, B(t) is the magnetic induction intensity at time t, and A is the cross-sectional area of ​​the induction coil (421); Defect information specifically includes: Assume that n defects are detected in total, and the defects are numbered 1, 2, ... n in the order of detection; Calculate the defect depth dn = k1·ΔVn and the defect length ln = v·ΔTn of the defect at position n; Where k1 is the depth coefficient; ΔVn is the range of the induced voltage at the nth defect; v is the transmission speed of the copper rod blank; ΔTn is the duration of the nth defect; Defect information also includes the defect quantity Nd: statistics Among them, Detect is the judgment function; ΔV i is the extreme difference of the induced voltage at the i-th defect; Δt i is the time interval between the i-th defect and the i-1-th defect; The specific judgment function Detect is: Construction Among them, V t is the set voltage change threshold, which is a constant; t min is the minimum interval between two sensing signals; S40: Calculate the density factor X1, the destructiveness factor X2, and the influence factor X3 based on the defect information; calculate the defect score Q of the copper rod blank = W1·X1+W3·X2+W3·X3, where W1, W2, and W3 are weight coefficients; and grade the copper rod blank according to the quality grade table; The density factor X1, the destructiveness factor X2, and the impact factor X3 are calculated as follows: Density factor X1 = Nd / L; Destruction factor Influence factor X3 = (l1 + ... ln) / L; Wherein, L is the total length of the copper rod blank; is the diameter of the copper rod blank.

2. The defect detection method for copper rod blank according to claim 1, characterized in that: Step S40 also includes storing the defect information, defect score and defect grade of the copper rod blank and generating a test report; and classifying and storing copper rod blanks of different grades.

3. A defect detection device for copper rod blanks, characterized in that: The defect detection method for a copper rod blank according to any one of claims 1 to 2 comprises: A transmission frame (1) is installed on the ground; A transmission roller (2) is provided on the transmission frame (1) and is used for conveying the copper rod blank to be tested; a plurality of semi-circular support claws (21) are provided at intervals on the transmission roller (2); the support claws (21) are opened upward, and the lowest inner wall thereof is flush with the upper end surface of the transmission roller (2) when viewed in the horizontal direction, and is used for supporting the copper rod blank; a detection area (22) is provided in the middle section of the transmission roller (2); An electromagnetic rotary drive device (3) is provided at each end of the detection area (22) along the transport direction of the transport roller (2) and is connected to the transport frame (1); the electromagnetic rotary drive device (3) includes a first electromagnetic coil (31), a first current regulator, and a first control unit; The first electromagnetic coil (31) is in a circular shape, with its opening facing the transport direction of the transmission roller (2), and the lowest end of the first electromagnetic coil (31) is lower than the transmission roller (2), and the inner wall diameter of the first electromagnetic coil (31) is larger than the diameter of the copper rod blank; The first current regulator is connected to the first electromagnetic coil (31), and the first control unit is installed on one side of the first electromagnetic coil (31) and is used to control the rotation of the copper rod blank; An electromagnetic induction detection module (4) is installed in the detection area (22), connected to the transmission frame (1), and located above the transmission roller (2), and is used to detect internal and surface defects of the copper rod blank.

4. The defect detection device for copper rod blanks according to claim 3, characterized in that: The electromagnetic induction detection module (4) includes a second electromagnetic coil (41), an electromagnetic sensor (42), a second current regulator, and a second control unit; the second electromagnetic coil (41) is coaxial with the supporting claw (21) and fixedly connected to the transmission frame (1); the electromagnetic sensor (42) is arranged on one side of the second electromagnetic coil (41) and connected to the transmission frame (1); the second current regulator is connected to the second electromagnetic coil (41), and the second control unit is installed on one side of the second electromagnetic coil (41) and is used to control the second electromagnetic coil (41).

5. The defect detection device for copper rod blanks according to claim 4, characterized in that: The electromagnetic sensor (42) comprises a plurality of independent induction coils (421) which are arranged in a spiral manner at different positions around the axis of the copper rod blank along the transmission direction of the transmission roller (2), and the spiral direction is opposite to the rotation direction of the copper rod blank.

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